High-frequency oscillation tube



A. G. THOMAS HIGH-FREQUENCY )SC ILLATION TUBE Jan. 4, 1949.

1 Filed D ec. 21, 1942 Inventor Altorney E Patented Jan. 4, 1949 UNITED STATES PATENT OFFICE HIGH-FREQUENCY OSCILLATION TUBE Albert G. Thomas, Lynchburg, Va.

Application December 21, 1942, Serial No. 469,602

11 Claims. (01. 2502'7.5)

This invention relates to electronic tubes and is an improvement over the tube shown in my U. S. Patent No. 2,305,646 issued December 22, 1942.

An object is to provide a tube that will produce ultra high frequency oscillations.

Another object is to provide a tube which uses broad streams of electrons oscillating at high frequency, thereby furnishing large currents.

A further object is the provision of a tube of simple construction, and which will provide relatively high current values at very high frequency.

Other objects will appear in the specification.

In the drawings:

Figure 1 is a part sectional elevation of an ultra high frequency tube.

Figure 2 is a front elevation of a pair of interleaved elements that may be used in the tube of Figure 1.

Figure 3 is a part sectional elevation of another form of ultra high frequency tube.

Figure 4 is a part sectional elevation of a variation of the tube of Figure 3.

Figure 5 is a part sectional elevation of another form of ultra high frequency tube, employing a beam of electrons.

In Figure 1, tube 1 contains cathode 2, which may have spaced wires in one plane. A battery or other source 3 for heating cathode 2 is connected as shown. Elements 4 and 5 of screening or other open-spaced conducting material, and preferably solid conducting plate 6, are provided on one side of cathode 2, and similar elements I,

8, and 9 are placed on the opposite side. Elements 4 and l are anodes of large mesh to allow free electron travel, and are connected respectively to plates 9 and 6 by means of wires or conductors I and l I. Element is connected to the positive terminal of potential source l2 the negative terminal of which is connected to cathode 2. Similarly, the positive terminal of potential source I3 is connected to element 8, and the negative terminal to cathode 2. It is possible of course that the potentials of sources l2 and. i3 might be in reverse order in some cases.

The surfaces of elements 5 and 9 may be treated to produce copious secondary emission, if desired. High resistance or other leaks l4 and I5, connected to wires H] and II, may be grounded to prevent excessive charges on the floating elements. Similarly any other part of the circuit may be arranged to drain off electrons to a source, or to the ground. Current or potential variations may be taken off between the cathode 2, and elements 6 or 9, or both, or from any other suitable element, or elements such as elements 5 or ,8. Inductive, capacitive, or even direct connections can be employed. 7

In operation, if by means of a temporary magnetic field, or a temporary connection, most of the electrons from cathode 2 are deflected to the left, say, then most of these electrons will pass through open mesh element 4, and screen 5 to strike plate 6, so that the secondaries Will be attracted to positively charged screen 5. When this happens however, the positive terminal of potential source I2 will in effect, be connected with element 1, so that the electrons will be attracted toward element I on the other side of cathode 2, thereby breaking the electronic connection between elements 5 and 6. The accelerated electrons then pass through open mesh elements 1 and 8, and strike secondary emitting element 9, so that the electrons ejected make a connection with element 8, made positive by source l3, so that element 4 is then charged positively to attract the electrons back to the other side of cathode 2 so that the cycle will be repeated at ,high frequency. High frequency oscillations will therefore result. The frequency may reach up into the high megacycle range.

It is not essential that secondary electrons be emitted by elements 6 and 9 as the accelerated stream of electrons may serve to bridge the gap successively between elements 5 and 6 and elements 8 and 9. These elements may be in two planes, in pairs, as shown in Figure 2 inwhich they are formed in interleaved fashion, in prongs, so that a pair may be in the same plane. In this waythe shielding efiect of one element on another may be minimized. The fluctuatin current may be taken off from element 6 or 9 or in any desired manner.

In Figure 3, tube [6 contains cathode ll, energized by current source I8, to which the negative terminal of potential source I9 is connected. The positive terminal of this source is connected with well screen 20 which is placed near plate 2!, which it, whereas plate 2| is placed on the opposite side at a greater distance. High resistance or other leak 24 may be connected between conductor 23, and the ground, to prevent the accumulation of excessive charges.

In operation, if mostof the electrons emitted by wire or grid-like cathode I! are magnetically or otherwise caused to pass through element to strike plate 2|, which may be secondary emitting. then the positive terminal of source l9 will in effect, be connected with anode 22, to make that plate positive. Since anode 22 is much closer to cathode ll than element 2| or element 29, the field will be more intense, and the electrons will be attracted back through the cathode to-'strike anode 22. When this happens however, the electrical connection between elements 20 and 2| will be broken, and anode 22 will lose its potentiaL,

and positively charged element 20 will again pull the electrons across, so that the process will be repeated. High frequency oscillations of large current value will therefore result. This tube Will be self-starting since element ZU'is positively charged, and will therefore not needa-starting magnetic field. The fluctuating current or potential can be taken from wire v23 or from any other suitable part of the tube. Wire 23 may be broken, anda device connected in that circuit, or a cathode connection can be used.

Theprinciples of the tube ofFigure 3 might be used to make a. duplex tube as shown in Figure 4. In this case the elements 25 and26 near the cathode would be perforated. The principles are the same except that a push-pull effect is used.

In Figure 5 is shown a variation of the tube described in the previously mentioned applications.

This tube is designed to be self-starting. Tube 21 contains electron gun 28, and deflection plates 29, and 30, .and secondary emitting element 3| placed as shown. This element'is part of or is connected to deflection plate 29. Electron receiving element 32 is sealed into the tube, and is connected with the positive terminal of. potential source 33, the negative terminal of which is connected with plate 39. Anode or connecting electrode 34 may be provided The gun. 28 is directed so that the electron beam normally strikes elements 3|, so that, the gap between elements 3 I, and 32 is made electrically conducting by secondary, or bridging electrons, with the result that plate 29 is charged positively. When this happens the beam is attracted to the left. so that it leaves element 3|, and strikes element-34, thereby breaking the electrical connection to plate 29. The beam will then fly back to strike'element 3! again, so that plate 29 will be recharged. and the cycle will be repeated at high frequency. It is'obvious that theelectron beam itself might be arranged to be part of the'circuit.

The impulses can be taken cit through element 34, or through some other part of the circuit. Since the beam normally strikes element 3!, this tube-will be self-starting. The tube can be duplex as shown in the prior applications, if desired.

Other variations in detail of the broad ideaof myjinvention are easily possible.-

What I claim is:

1. An electronic tube-comprising, a cathode, an electron receiving element adjacent said cathode; a secondary emitting element on the opposite side of said cathode and at greater distance therefrom than said electron receiving element, an apertured electron accelerating element between said secondary emitting element and said cathode and closely-adjacent said secondary emitting element.

4 said electron receiving element and said secondary emitting element being electrically connected.

2. In an electronic tube, a cathode, an anode immediately adjacent said cathode, and electronic switch means including a secondary emitter element oppositely positioned from said anode with respect to said cathode, said switch means being connected in a charging circuit including said anode and said cathode, and said anode acting to remove electrons from said switch means to reduce the degree of said charging.

3. In an electronic tube, a cathode, an anode immediately adjacent said cathode, and electronic switch means including a secondary emitr ter element "and an accelerating'element, op-

positely positioned from said anode with respect to said cathode, said switch means being connected in a charging circuit including said anode by, means of electrons, and said anode acting to remove electrons from said switch means to reduce the degree of said charging.

4. In an electronic tube, a cathode, an anode immediately adjacent said cathode and substantially in alignment therewith, and electronic switch means including a secondary emitter element oppositely positioned from said anode with respect'to said cathode and in substantial alignmenttherewith, said switch means being connected'in a charging circuit for said anodeby means of electrons, and said anode acting to establish a field to remove electrons from said switch means to reduce the degree of said chargmg.

5. Same as in claim 4, said secondary emitter element being at greater distance from said cathode than said anode.

6. In a high frequency electronic tube system, a cathode, an anode adjacent said cathode, electronic switch means including a secondary emitter element and an accelerating element adjacent thereto .and oppositely positioned from said anode with respect to said cathode, meansforcharging said accelerating element continuously positively with respect to said cathode, and a conductor connecting said secondary emitterelement and said anode.

7. Same as in claim 6, said secondary=emitter element being at greater distance from said cathode than said anode.

8. Same as in claim 6, said cathode being directly between said. secondary emitter element andsaid anode and substantially coextensive in dimensions therewith.

9. An electronic tube system comprising, a cathode, an anode adjacent said cathode, atsecondary emitter element positioned oppositely from saidaanode with respect to' said cathode-and conductively connected with said anode, an apertured accelerating element between said cathode and said secondary emitter element, and means forcharging said accelerating element positively with respect to said cathode.

L0.- In a high frequency electronic tube system, a pair ofelectronic switches including secondary emitterelements and adjacent electron acceleratingelements, a'cathode between said switches, means-for charging said accelerating elements positively with respect to said cathode, an apertured anode adjacent-said cathode, electrically conductive means connecting said anode with the secondary emitter element on the opposite side ofsaid cathode, an apertured anode adjacent said cathode on the opposite side thereof from said first namedanode, and electrically conductive means connecting-said anode with the secondary emitter element on the opposite side of said cathode therefrom.

11. Same as in claim 10 and including electron leakage means for said anodes.

ALBERT G. THOMAS.

REFERENCES CITED UNITED STATES PATENTS Number Name Date Poole July 11, 1942 Number 6 Name Date Pierce, Jr Apr. 17, 1923 Tolmie, et a1 Nov. 20, 1928 Loewe Mar.14, 1933 Kurth May 16, 1933 Clavier May 15, 1934 Steimel Sept. 15, 1936 Lux May 3, 1938 Goodrich May 10, 1938 White Jan. 10, 1939 Banks July 4, 1939 Bruining, et a1 Apr. 23, 1940 

